Report: Plastic Intake Manifold May Crack Causing Coolant Leak
Mercury Mountaineer Problem
Electrical & Lights Affected: 4.6L V8
Average Mileage: 115,623 mi (47,000 mi - 200,200 mi)
The composite (plastic) intake manifold may crack near the thermostat housing and cause a coolant leak. Ford released an updated manifold that was reinforced to prevent a recurrence. No recall was issued for this problem but Ford did extend the warranty to seven years on some models from the date of purchase.
Visitor, 1999 Mercury Mountaineer, 76,220 mi
Driving down the road, pressed gas pedal and white smoke started coming out back. I pulled over and antifreeze was all over the inside of the engine and hood. Looked and intake manifold where thermostat is housed was completely cracked. It's been leaking for the past month causing antifreeze to cause the ignition coils in cylinder 7 and 8 to go bad. Now it's completely cracked. A shame ford never officially recalled this, poor design that is now costing consumers a hefty bill for a new intake manifold to replace something that wasn't manufactured right to begin with!
Visitor, 2005 Mercury Mountaineer, 81,000 mi
Manifold leaking. Causing coolant to leak into spark plugs which is shorting them out. Truck isn'r even paid for.
Visitor, 1999 Mercury Mountaineer, 150,000 mi
When idling my vehicle has a steady drip of "water" from the tailpipe
Visitor, 2002 Mercury Mountaineer, 189,000 mi
This problem will cause water to leak into the cylinders and cause them to miss fire making you think there is a problem with the plugs and coils. The car will run horribly but if you look closer you will find that it is in dead the plastic piece under the thermostat housing. It is a real pain. I am still trying to get his fixed and I am sure it is going to cost me a lot of money because it is no longer under warranty.
Visitor, 2002 Mercury Mountaineer, 120,000 mi
Ammonia smell, after 2 days bad coolant leak. Plastic intake manifold cracked. Warrenty covered replacement .
Visitor, 2005 Mercury Mountaineer, 75,798 mi
Noticed car was leaking coolant, took it to the mechanic who diagnosed the cracked plastic intake manifold. Ordered a new part ($415.00) and fixed the problem.
Visitor, 2004 Mercury Mountaineer, 92,000 mi
Big puddle of coolant under the truck and found that the leak was in two spots, intake manifold and water pump. Repairs cost 1200 +, but the warranty company will foot the bulk of the bill.
Visitor, 2004 Mercury Mountaineer, 100,058 mi
I just purchased this vehicle from a private seller. I saw that it was leaking coolant but got a good price on the mountaineer so purchased it anyway. I took it in to get inspected and had every problem listed on this forum. intake manifold was cracked could not find anywhere but dealer cost 700.00 with labor. It also needed rear bearings and hubs replaced and the back emblem has a crack around it. Total cost to repair all problems 1400.00. That bill should go directly to ford because this is a problem that seems to occur on many of the mountaineers.
Visitor, 2002 Mercury Mountaineer, 141,000 mi
Had car diagnosed for not starting...ground wires were cleaned and the intake manifold was found to be damaged...replacement cost around $650!
Visitor, 2002 Mercury Mountaineer, 77,000 mi
minor water leak found. When further check was done it was found that it had a leak in the crossover below the thermostat housing where it bolts to the intake manifold. Matches the recall but past the 7 years so am looking at $1,000 to fix something that Ford/Mercury knew was a problem but did not tell us about.